The following is a chronology of recent events concerning North and South Korea, and the United States.

July 4, 2017: North Korea succeeds for first time in test-firing intercontinental ballistic missile.

July 28: North Korea launches its second ICBM, unusually late at night.

September 3: North Korea conducts its sixth nuclear test.

September 15: North Korea fires intermediate-range ballistic missile over Japan into the Pacific with flight distance of 3,700 kilometres, the longest yet, putting the US territory of Guam within range.

September 19: US President Donald Trump, in his speech at the United Nations, calls North Korean leader Kim Jong-un a “Rocket Man” who is “on a suicide mission,” and warns that the United States may have to “totally destroy” North Korea.

November 20: Trump announces re-listing of North Korea as a state sponsor of terrorism, following delisting in October 2008.

November 29: North Korea fires its third ICBM. The missile, covering flight distance of 1,000 km and reaching altitude of over 4,000 km, is suspected to have longer potential range than previously launched ones.

January 1, 2018: Kim, in New Year’s address, expresses readiness to send athletes to Winter Olympics in Pyeongchang, South Korea.

January 4: The United States and South Korea agree to postpone annual joint military exercises until after Winter Olympics and Paralympics.

January 9: North and South Korea agree at ministerial-level talks to the North sending athletes to the Olympics.

February 9: North and South Korean athletes march together under a unified Korean flag at the Olympics’ opening ceremony.

February 10: South Korean President Moon Jae-in and Kim Yo-jong, sister and close aide to Kim Jong-un, hold talks in Seoul. The North invites Moon to visit North Korea.

February 23: The United States announces a slew of measures against North Korea that Trump called the “heaviest” sanctions ever imposed on the country.

February 25: High-level North Korean official visits South Korea for Olympics’ closing ceremony, meets with Moon in Pyeongchang.

March 5: South Korea’s special envoys visit North Korea and hold talks with Kim Jong-un.

March 6: South Korea’s presidential office unveils the outcome of the envoy’s meeting with Kim, including agreement of a summit meeting between the two Koreas in late April.

March 8: Senior South Korean official says Trump said he would meet Kim by May to achieve permanent denuclearisation.